Windows Server 2008/2008R2/2012 servers allow two simultaneous Remote Desktop sessions. You may choose to disable multiple RDP sessions if desired. If only one session is available and you take over another person's live session, you may choose to enable multiple RDP sessions. This article describes the process for disabling and enabling multiple sessions.

How to Enable/Disable Multiple RDP Sessions in Windows Server 2012

By default, Windows Server 2012 servers allow a single Remote Desktop session. If only one session is available and you take over another person's live session, you may choose to enable multiple RDP sessions. This article describes the process for enabling and disabling multiple sessions.

Enable Multiple RDP Sessions

Log into the server using Remote Desktop.

Open the start screen (press the Windows key) and type gpedit.msc and open it